I do not know President Monson personally. But his history is well known to all of us. He was a Bishop while in his 20’s, a Stake President shortly thereafter, and then called in his late 30’s to be a member of the Quorum of the Twelve. He worked for Deseret News before becoming a full time General Authority. Essentially his entire life has been church service, both in his profession and in his calling.
If you want to see what The Church of Jesus Christ of Latter-day Saints would produce if a life were entirely the product of the institution and experiences derived from serving in and under that institution, you have that in President Monson.
It is clear to me that he absolutely trusts the system which produced all his significant life experiences. The last two vacancies in the Twelve were filled by the senior president of the Seventy. This would make Elder Ron Rasband the next one in line to fill a vacancy in the Twelve. He (Elder Rasband) is a member of my stake.